Originally posted by dlneubec
What I noticed in comparing your clean driver and the EnABL'd one below it is the changes in the upper midrange, from about 2khz to 7khz or so. It appears to my untrained eye that the decay is faster, the decay lines are more uniform (less peaking in the lines) and the lines are more consistently spaced than in the untreated driver.

Here is a comp of those 2 charts to enable easier comparison... red is clean. Blue (EnABL) on top so anywhere you only see blue means that the red curve is right underneath.

when you move the mouse over one of the CSD plots the Clean Driver CSD plot will appear. Moving the mouse off the plot and the CSD for the treated driver appears. This shows very dramatically the change due to the treatmnet. You will see the differences in deacy, changes in resonant frequencies and changes in resonance Qs. Very dramatic.

One thing I find distrubing is that the full enable treatment, in this case, tended to make the first few resonance higher Q and more defined.

I also added a CSD at the bottom which compares Mortite 1(mouse off) with Full Enable (mouse on).
Make sure you give the page time ot load fully. It can yake a while with dial up.

when you move the mouse over one of the CSD plots the Clean Driver CSD plot will appear. Moving the mouse off the plot and the CSD for the treated driver appears. This shows very dramatically the change due to the treatmnet. You will see the differences in deacy, changes in resonant frequencies and changes in resonance Qs. Very dramatic.

One thing I find distrubing is that the full enable treatment, in this case, tended to make the first few resonance higher Q and more defined.

I also added a CSD at the bottom which compares Mortite 1(mouse off) with Full Enable (mouse on).
Make sure you give the page time ot load fully. It can yake a while with dial up.

The image swap with the cursor is helpful. I'll have to remember that for new pages where it would be useful.

Quote:

Originally posted by john k... One thing I find distrubing is that the full enable treatment, in this case, tended to make the first few resonance higher Q and more defined.

The same thing occurs when tweaking the surround directly the way manufacturers have for more than a decade. The mod I made to the Insignia was inspired by the better drivers that often were treated this way. Since the issue is the mechanical impedance at the junction and it being a complex one, it's frequency dependent (as you know) and will not IME show uniform change across the spectrum when treated, just as you show for your tests of diaphragm mods.

I noted the same issues in my writeup of that Insignia mod. Some areas showed some detrimental changes, but the passband being the focus and most important aspect, my copying of the manufacturers' commonly found "tweak" shows some resonances being reduced while some had higher magnitude and Q.

The major first resonance mode around 1KHz is greatly improved, but the upper area resonances are made a bit worse with very little change at the top end. Since this is a mid-woofer, the crossover will help by pushing all of the upper area down into the stop band, of course. The changes in the distortion amplification of non-linear motor distortion and harmonic distortion I never measured. I still have the original MLS measurements and could show the harmonic distortion that LAUD extracts from them, but it's going to be limited to the lower orders due to the 48K sampling frequency.

Interestingly, there's essentially no change at all above about 9K for this driver. It's a woven diaphragm driver, so the upper breakup seems to be defined almost exclusively by the properties of the diaphragm totally isolated from the surround, or so it appears.

I use mortite for gaskets when I mount drivers and to damp horns- seems to sound better - I was wondering if you just placed tiny dabs on the cone or you put any thought to it beyond that? Sure looks prettier then stock or 'enable' - How big were the dots? Maybe small dabs of silicon glue would be similar but permanent. I can see a drum roll coming on and little dots of mortite being propelled at me